1. Field of the Invention
The present invention relates to an image sensor, and is more particularly concerned with a multi-layer image sensor structure having orthogonally related semiconductor and electrically conductive electrodes which are separated by an electrically insulating layer.
2. Description of the Prior Art
A simple technology is required for image sensors, which sensors permit a small defect density of large surface arrays. Futhermore, a dot-shaped defect, which renders an image sensor useless or a selection element useless, is only noticeable as a dot-shaped image defect and not as a defect of an image line or an image field. According to CCD principles, an example of which is illustrated in the publication "Carrier Diffusion Degradation of Modulation Transfer Function in Charge-Coupled Images" by D.H. Seib in the IEEE Vol. ED-21, No. 3, 1974, Pages 210-217, CCD devices do not comply with these requirements. However, the publication "Charge Injection Imaging" by G. J. Michon and A. K. Burke, Digest of the ISSCC, 1973, Page 138, offers a first step for the solution of these problems with its dot-by-dot readout. However, it is a drawback of this arrangement that the readout signal occurs as a current at a substrate electrode which has a relatively great capacitance with respect to ground. The signal voltage occurring is relatively small since the substrate capacitance grows in proportion to the number of integrated sensor elements. This causes a limitation in the resolution or sensitivity of the sensor in the case of a given sensitivity of the signal amplifier.